Steam-engine indicator.



Nn. 695,227. Patented mar. |902. A. F. NAGLE.

STEAM ENGINE INDICATOR.

(Application led July 6. 1901.) (No Model.)

:Hz cams Farms e9.. PHoraLmm., WASHINGTON m'inesses:

gyl @QM ilivrrnn @raras Farrar @risica AUGUSTUS NAGLE, OF MONTCLAIR, NEV JERSEY, ASSIGNOR TO EARLE II. GOWING, OF READING, MASSACHUSETTS.

STEAM-ENGINE INDICATMOR.

SPECFCATQN forming part of Letters Patent No. 695,227, dated March. 11,1902, Application 'lecl July 5, 1901. Serial No. 67,345. (No model.)

T @ZZ whom it 11m-y concern:

Be it known that I, AUGUSTUS F. NAGLE, of Montclair, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Steam-Engine Indicators, of which the following is a specification.

This invention has for its obj ect to provide an efficient, reliable, and durable integrating Io mechanism for determining continuously the amount of power developed by an engine.

The practice with instruments heretofore commonly used is to take an indicator-diagram at intervals of five, ten, or fifteen minutes and work up the horse-power from the measured area-of the diagram. It is a well- `known fact that in nearly all steam-engines, and especially in those used for electric power, the work is constantly changing, so

zo that no periodical indications such as are obtained by this'means give a correct measurement of the average power.

My invention and improvements relate to continuous measurements instead of interz 5 mittent ones, as hereinafter described and claimed.

Of the accompanying drawings, forming a part of this specification, Figure 1 represents a side elevation of an indicator embodying 3o my invention. Fig. Zrepresents a section on line 2 2 of Fig. l. Fig. 3 represents a top plan view. Fig. A represents a side elevation,

y partly in section, the lower portion of the cylinder being broken away.

3 5 The same reference characters indicate the same parts in all the figures.

In the drawings, o, representsthe cylinder of my improved indicator, having at one end a coupling or other suitable means for con- 40 nection to a pipe or passage communicating with the engine-cylinder.

ZJ is apistonfitting the cylinder a and held normally in the position shown in Fig. 2 by a duplex spring c, interposed between the piston and the cylinder-head a2. The upper end portion of the piston-rod d is adapted to oscillate or swing slightly fora purpose hereinafter described. This movement is permitted in the construction shown in Fig. 2 by 5o means of a ball 2, formed on the lower end of the piston-rod and supported by the concave or cupped end of a screw 3, inserted in the bottom of the piston. The central portion of the piston is cupped above the screw 3, the cupped portions of the screw and piston and the ball on the piston-rod forming a movable joint, which permits the oscillation referred to. The ends of the members of the duplex spring c are affixed to nuts c' c2, which are secured, respectively, to the cylinder-head 0.2 6o and piston b.

The piston-rod d is extended through an opening in the cylinder-head a2, said opening being of sufficient diameter to permit the swinging movement of the rod.

c represents a yoke which is rigidly attached to the outer end of the rod CZ. Said yoke is provided at its upper and lower ends with pivots f f located in the center line of the rod, which engage and rotatively support 7o an elongated gear or pinion g, the pivot f being formed as an adjustable screw.. Attached to or forming a part of the elongated gear g is a friction-wheel h, of greater diameter than the gear.

represents adisk formed on or attached to a shaft or stud i', which is journaled in a bearing j, affixed to the cylinder-head a2. The side or face i2 of the vdisk c' is in a plane which y is parallel with the direction of movement of 8o the piston and yits rod and is frictionally engaged with the friction-wheel h the latter being yieldingly pressed toward the disk e by means presently described. The frictionwheel 7?, and disk i are preferably made of 85 hardened steel.

The disk c' is oscillated forward and backward by means of a grooved pulley m, affixed to the shaft i and engaged with a cord connected with the cros -head of the engine, and 9o a spring n, Fig. 4t, scnred at one end to the pulley and at the other to the bearing j, the cord acting to rotate the pulley and the disk il in one direction, while the spring rotates the pulley and disk in the opposite direction. A stop-arm o, affixed to the cylinder-head, cooperates with a stop-arm p, afxed to the pulley m, in limiting the movement imparted to the pulley and disk by the spring fn.

The elongated gear g and friction-wheel h loo move with the piston b, the latter being reciprocated in the cylinder by the alternate action of steam from the engine-cylinder and of the spring c, the steam-pressure forcing the piston outwardly against the pressure of the spring. When the steam-pressure is relieved, the spring reacts and forces the piston inwardly. The friction-wheel h is so arranged that when the piston is at the extreme lower end of its movement the point of contact between said friction-wheel and the face t2 of the diskz' is a considerable distance above the center of said disk, as shown in Figs. l and 4, and when the piston is moved upward by steam-pressure the said point of contact is moved farther away from the center of the disk, the entire movement of the frictionwheel being at one side of the center, thereby preventing injury from the destructive grinding action which might occur if the wheel 'traveled across the center.

Theloscillations of the disk t' impart corre'- sponding movements to the friction-wheel h and elongated gear g, the amplitude of said movements depending on the distance between the center of the disk and the point where the wheel and disk are in contact, this distance being determined by the strength ot' the spring c and by the steam-pressure.

The elongated gear g is a member of a train ot' gears, the other membersof said train being mounted on a suitable stand q, attached to the cylinder-head a2 and provided with pointers, placed over dials s on said stand. The length of the elongated gear is sufficient to maintain the engagement with the train of gears at all positions of the piston. The advanced motion imparted to the friction-wheel h and gear g bythe disk't' is therefore shown by the pointers through the members of the geartrain.

The means hereinbefore alluded to formaintaining an operative frictional contact lbetween the friction-wheel h and disk t' (such maintenance being made feasible by the rocking or jointed connection between the pistonrod d andthe piston) are as follows: The yoke e is held in rectilinear position by the guides t' t, to which its two sides are suitably iitted. The guides are connected at the top'by a cross-piece t2. At the bottom they are pivoted to projecting ears on the cylinder-head, the axis of the pivots being parallel to the plane of the disk, and by this means the guides are adapted to swingin and out toward the face of the disk. The inner sidesof the guides t' are provided with 1ongitudinal'grooves t3,which receive rollers u u', mounted 'on the sides of the yoke e, said rollers being adapted to travel in the grooves t3 and 'by'their bearing on the Walls of said grooves maintaining an engagement between thefyoke and the'frame @whereby the yoke is causedv to partake of any sidewise movement imparted tothe guides. t* represents a cross-ba-rfattachedto the guidest, below the` upper end thereof. 'U represents a spring which is interposed betweenl the cross-bar t"l and a screw-threaded spring-abutment w, ad-

j ustably engaged with a tapped socket in a stand q' on the cylinder-head, said stand sup-- the cross-bar t* and extending through an opening in the abutment w, the rod being adapted to slide in the abutment. portion of the rod fw is screw-threaded, and a nut @u2 is engaged with the threaded portion of the rod, said nut serving to draw said guides away from the disk when it is desired to temporarily withdraw the friction-wheel 7L from contact with the disk.

The connection between the piston-rod yoke e and the swinging guides t' aiforded by the rollers u and grooves t3 is relatively antifrictional, and the swinging guides enable a light spring to maintain a suitable'frictional connection between the wheel h and disk t', so

The outer that the wear of said parts is reduced to a ,i

minimum. f

The operation of the instrument is as fol` lows: The spring n and the motion-reducing mechanism connected with the pulley mand with the cross-head of the engine impart a backward-and-forward motion to the disk t",

and the steam-pressure acting upon the piston and upon the spring c forces the piston upward and determines the position'of the friction-wheel 7L. It does not matter where the exact location of this wheel may be, for the difference between the steam and exhaust pressure is what is recorded-#that is, when the steam is admitted the wheel h is moved upward and receives and imparts to the train of gears rotary movements of an extent or amplitude which increases with the upward. movement of the friction-wheel h, and when the steam is exhausted the friction-wheel h receives and imparts to the train of gears ronumber of revolutions made bythe friction' Wheel h.

y represents a ring having a hub y', which is secured by a set-screw y? to the bearing j, the periphery of the ring being concentric with the shaft t and graduated into divisions of equal length, the graduations beingpreferably arranged to dividethe periphery of the ring into one hundred parts. On the periphery of the'ring are two slides or sliding pointers Z a', which are heldi'n engagement with the ring by ears formed on their edges, as shownin Fig. 4.

T-he pulley m has a laterally-projecting-iinger z', which alternately-strikes one and the other of said slides'as the pulley rotates backward and forward and causes the-slides to cooperate with the graduationson the ringy in IOO IIO

indicating the amplitude orlength of the rotary movements of the pulley, and therefore of the disk e'. This indication is an element in the calculation of the amount of power indicated. Y

To determine the horse-power from the instrument, the reading of the dials is taken for any desired period of time and the number of revolutions calculated for one minute. The indicated horse-power of one end of the cylinder is computed by the use of the formula I.H.P.=C N2 in which N number of revolutions per minute of disk-Wheel h, indicated by dials.

C coefficient, depending on the number of spring, the arc of motion of disk, and size of the engine, which for any given engine and adjust-ment of instrument is constant.

The coefficient C isdetermined from formula I-I. P. constant'X l lb. m. e. p.`

Z lstroke per min. X scale of spring Fractional part of disk rotation the For example, suppose for a periodicil five minutes the total number of revolutions of friction-wheel is one hundred and eighty. Then the revolutions per minute Suppose an engine having tWenty-inchcylinder, five-foot stroke, the horse-power constant for one pound mean effective pressure. One stroke per minute' is area 1570.8 2 6. 33000 0&7

Suppose scale of spring is eighty and the fractional part of disk rotation is seven-tenths. Then Then indicated horse-power developed by one end of cylinder I. H. P. 5.44: X 36 195.84.

The formula LH.P.=CXN,

given above, is Worked out as follows: Let

NOW the mean effective pressure P, referring to the instrument, is obtained from the formula N X S X D R X T X 2 E or when D 2E :Nxs

R X T Consequently I. H. P. (one end of cylinder) Having thus explained the nature of my invention and described a Way of constructing andusing the same, though Without attempting to set forth all the forms in which it may bemade 0r all the modes in which it may be used, What I claim, and desire to secure by Letters Patent, is

1. An integrating-indicator or power-meter comprising a cylinder, a piston therein, a helical spring connecting thesame to the cylinder-head, a piston-rod extending from the cylinder, and a yoke affixed to the outer end of the piston rod and provided with pivots placed in the line of the piston-rod, an elongated gear and a friction-wheel supported-by said pivots and a friction-disk adapted to be oscillated and presenting a fiat side to said friction-Wheel. 1

2. An integrating-indicator or power-meter, l

comprising a cylinder, a piston therein, a helical spring connecting the same `to the cylinder-head, a piston-rod extending from the cyl- `inder, its upper portion being laterally movable, and an elongated gear and a friction- Wheel, both supported by the laterally-movable upper portion of the piston-rod, a fric- IOO IIC

der-head, a piston-rod extending from the cylinder and laterally movable at its upper portion, a yoke" affixed to the outer end of the piston-rod, an elongated gear and a frictionwheel supported by said yoke, pivoted guides engaged with said yoke, a friction-disk adapted to be oscillated and presenting a fiat side to said friction-wheel, and a spring for yieldingly pressing said pivoted guides toward the disk and thereby maintaining an operative frictional contact between the said friction wheel and disk. l s

4. An integrating-indicator,or power-meter, comprisinga cylinder, a piston therein, a helical spring connecting the same to the cylinder-head, a piston-rod extending from the cylinder and laterally lnovable at its upper portion, a yoke affixed to the outer end of the piston-rod, an elongated gear and a frictionwheel supported by said yoke, pivoted guides for the yoke, said guides and yoke having antifrictional engaging members such as rollers and grooves, a friction-disk adapted to be oscillated and presentinga flat sideto said friction-wheel', and a spring for yieldin gly pressing said pivoted guides toward the disk and thereby maintaining an operative frictional contact between the said friction wheel and disk.

5. A11integrating-indicatororpower-meter, comprising adisk, means for oscillating it,and indicating mechanism operated by the movements of the disk, a cylinder, a spring-propelled piston therein, a helical spring connecting the same to the cylinder-head, a piston-rod connected with said indicating mechanism, a xed graduated ring concentric with the axis of the disk, and adjustable slides or pointers movable on the graduated periphery of said ring.

In testimony whereof I have affixed my signature in presence of two witnesses.

AUGUSTUS F. NAGLE. Witnesses:

B. M. BERRY, B. S. PARKER. 

